<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<form action="/login.do" method="post">
    登录(默认的4个用户id:[1,2,3,4])
    用户Id:<input type="number" name="userId"/>
    <input type="submit" value="登录"/>
</form>
</body>
</html>